I. Field of the Present Invention
The present invention relates generally to turbine engine constructions and, more particularly, to the structure of a diffuser system disposed downstream of centrifugal compressor in a turbine engine.
II. Description of the Prior Art
In a turbine engine having a centrifugal compressor, flud is discharged under pressure radially outwardly from the rotating shaft of the turbine. The turbine engine housing includes passages which direct the fluid toward a combustor chamber formed in the housing. In order to obtain controlled flow characteristics in the discharged fluid so that the fluid mixes and ignites efficiently and completely in the combustor chamber, a diffuser system is often employed in the passage between the centrifugal compressor and the combustion chamber.
Typically the diffuser comprises a pair of annular, radially extending walls a fluid flow passage therebetween sized to provide the desired flow characteristics. In addition, vanes may extend across the passageway between the radially extending surfaces to further control the direction and velocity and flow envelope of the fluid flow from the diffuser. However, the flow pattern created by the diffuser can be modified or destroyed if the passageway changes direction. Thus, unless the combustor chamber is located radially outwardly from the diffuser passageway, the turbine engine will not perform as efficiently as intended by incorporating the radial diffuser.
Accordingly, in the design of a turbine engine which is to be enclosed in a narrow turbine housing, it would be advantageous to place the combustor chamber axially downstream from the centrifugal compressor to provide a turbine engine with a minimum breadth. In such a case, it will be understood that the fluid discharged by the compressor must be axially displaced toward the combustor chamber. During this transfer to the combustor chamber, it would be advantageous to provide additional means for controlling and directing the flow of fluid into the combustor chamber so that the fluid is well dispersed in the combustor chamber. Previously, such control was provided by swirl plate constructions incorporated in the walls of the combustor housing. In such a device, the combustor chamber must be specially constructed and thus adds to the cost and complexity of the turbine engine construction. On the other hand, the housing walls defining the flow passages could also be specially constructed to include diffuser means which would also substantially increase the cost and complexity of the turbine engine.